code: def __str__(self):
      return (
          f"MQ(host={self.host}, port={self.port}, union_name={self.union_name}, "
          f"policy_id={self.policy_id}, route_table={self.route_table})"
      )
  
imports: import json
  from logging import getLogger
  from typing import List, Optional
  from fate.arch.federation.api import PartyMeta
  from fate.arch.federation.message_queue import MessageQueueBasedFederation, Party
  from ._mq_channel import MQChannel
  from ._rabbit_manager import RabbitManager
label_desc: Use image node_id 2 for calling the MQ obj's underlying member method code with example usage: obj.__str__() and returns: str, self, str, self, str, self, str, self, str, self, str